1,743 research outputs found

    Scale Effects, Technical Efficiency and Land Lease in China

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    Using a panel dataset from Zhejiang province in China over the period 1995-2002, we propose a two-step estimation procedure to investigate the links between land lease activity and production efficiency. We find that the output elasticity with respect to land, the scale effect and the technical efficiency are higher for farmers involved in land-lease activities. In addition, technical efficiency and land-lease activity are endogenous, and farmers with higher technical efficiency are more likely to lease more land and adopt advanced technologies to achieve higher profits, which in turn alters the technical efficiency.Land Lease, Land Use Rights, Technical Efficiency, Scale Effect, Farm Management, Land Economics/Use, Q15, P23, D50,

    Rational Expectation and Education Rewarding: The Case of Chinese Off-Farm Wage Employment

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    This study establishes a life-cycle model that a representative agent chooses optimal time of education to maximize his/her life earning, which implies that there may exist nonlinear relation between education and earning. Using the data of Chinese off-farm wage employment, we find that the duration of schooling years will increase by 1.7 years with 1 percent increase in rate of return to education. The empirical results also indicate that controversies about return to education might arise from model misspecification without consideration of nonlinearity and sample selection.return to schooling, life-cycle model, rational expectation, China, Labor and Human Capital, I20, J43, Q01,

    Analytical results for a parity-time symmetric two-level system under synchronous combined modulations

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    We propose a simple method of combined synchronous modulations to generate the analytically exact solutions for a parity-time symmetric two-level system. Such exact solutions are expressible in terms of simple elementary functions and helpful for illuminating some generalizations of appealing concepts originating in the Hermitian system. Some intriguing physical phenomena, such as stabilization of a non-Hermitian system by periodic driving, non-Hermitian analogs of coherent destruction of tunneling (CDT) and complete population inversion (CPI), are demonstrated analytically and confirmed numerically. In addition, by using these exact solutions we derive a pulse area theorem for such non-Hermitian CPI in the parity-time symmetric two-level system. Our results may provide an additional possibility for pulse manipulation and coherent control of the parity-time symmetric two-level system.Comment: 7 pages, 4 figure

    Understanding and Improving Recurrent Networks for Human Activity Recognition by Continuous Attention

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    Deep neural networks, including recurrent networks, have been successfully applied to human activity recognition. Unfortunately, the final representation learned by recurrent networks might encode some noise (irrelevant signal components, unimportant sensor modalities, etc.). Besides, it is difficult to interpret the recurrent networks to gain insight into the models' behavior. To address these issues, we propose two attention models for human activity recognition: temporal attention and sensor attention. These two mechanisms adaptively focus on important signals and sensor modalities. To further improve the understandability and mean F1 score, we add continuity constraints, considering that continuous sensor signals are more robust than discrete ones. We evaluate the approaches on three datasets and obtain state-of-the-art results. Furthermore, qualitative analysis shows that the attention learned by the models agree well with human intuition.Comment: 8 pages. published in The International Symposium on Wearable Computers (ISWC) 201

    Direct Observation of Photoinduced Charge Separation in Ruthenium Complex/Ni(OH)\u3csub\u3e2\u3c/sub\u3e Nanoparticle Hybrid

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    Ni(OH)2 have emerged as important functional materials for solar fuel conversion because of their potential as cost-effective bifunctional catalysts for both hydrogen and oxygen evolution reactions. However, their roles as photocatalysts in the photoinduced charge separation (CS) reactions remain unexplored. In this paper, we investigate the CS dynamics of a newly designed hybrid catalyst by integrating a Ru complex with Ni(OH)2 nanoparticles (NPs). Using time resolved X-ray absorption spectroscopy (XTA), we directly observed the formation of the reduced Ni metal site (~60 ps), unambiguously demonstrating CS process in the hybrid through ultrafast electron transfer from Ru complex to Ni(OH)2 NPs. Compared to the ultrafast CS process, the charge recombination in the hybrid is ultraslow (≫50 ns). These results not only suggest the possibility of developing Ni(OH)2 as solar fuel catalysts, but also represent the first time direct observation of efficient CS in a hybrid catalyst using XTA
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